Internship | Physics-Based Model Implementation on a Battery Management System

Battery packs consist of many individual battery cells connected in series or parallel. To ensure proper functioning of all the individual cells, they are monitored by a Battery Management System. This consists of a read-out circuit, which does basic measurements like voltage, current and temperature, and a controller, which computes operational parameters such as the state-of-charge of the batteries. At the heart of the controller, a model of the batteries is used to estimate internal states based on measurable external parameters such as voltage and current or to make predictions about it behaviour in the near future.

Currently, the applied model is typically empirical, meaning that it focusses on predicting output (voltage) based on input (current). While this model can effectively be used for some tasks, it is not suitable for monitoring or enforcing physical limits inside the cell. For this reason, Physics-Based Models (PBMs), which can simulate internal potentials and concentrations inside the cell including ageing reactions, have received significant attention in research and industry. Concrete applications of these models can be to govern fast charging by monitoring the anode potential or to provide power limits which prevent ageing. However, to unlock this potential, the PBM needs to be simulated on the BMS controller. Given that it’s computational footprint is significantly larger than empirical models, this is not trivial.

The goal of this internship is to explore the trade-off between model fidelity and computational load. You will model the PBM in Simulink and compile C-code which will run on an embedded BMS platform. The goal is to run the PBM with a footprint that is small enough to leave room for other algorithms while ensuring that its accuracy is sufficient for BMS tasks. The footprint can be influenced by exploring different well known simplified PBMs such as the single particle model.

Assignment tasks:

• Explore the various PBM simplification forms;
• Implement the PBM in Matlab/Simulink;
• Generate and run the code on the target platform;
• Explore the trade-off of model performance and computational load.

You want an internship opportunity on the precursor of your career; an internship gives you an opportunity to take a good look at your prospective future employer. TNO goes a step further. It’s not just looking that interests us; you and your knowledge are essential to our innovation. That’s why we attach a great deal of value to your personal and professional development. You will, of course, be properly supervised during your work placement and be given the scope for you to get the best out of yourself. Furthermore, we provide:

• A highly professional, innovative internship environment, within a team of top experts.
• A suitable internship allowance (615 euro for wo-, hbo- and mbo-students, for a full-time internship).
• Possibility of eight hours of free leave per internship month (for a full-time internship).
• A free membership of Jong TNO, where you can meet other TNO professionals and join several activities, such as sports activities, (work-related) courses or the yearly ski-trip.
• Use of a laptop.
• An allowance for travel expenses in case you don’t receive an OV-card.

At TNO, we innovate for a healthier, safer and more sustainable life. And for a strong economy. Since 1932, we have been making knowledge and technology available for the common good. We find each other in wonder and ingenuity. We are driven to push boundaries. There is all the space and support for your talent and ambition. You work with people who will challenge you: who inspire you and want to learn from you. Our state-of-the-art facilities are there to realize your vision. What you do at TNO matters: impact makes the difference. Because with every innovation you contribute to tomorrow’s world. Read more about TNO as an employer.

At TNO we encourage an inclusive work environment, where you can be yourself. Whatever your story and whatever unique qualities you bring to the table. It is by combining our unique strengths and perspectives that we are able to develop innovations that make a real difference in society. Want to know more? Read what steps we are taking in the area of diversity and inclusion.

After the first CV selection, the application process will be conducted by the concerning department. TNO will provide a suitable internship agreement. If you have any questions about this vacancy, you can contact the contact person mentioned below.

Important to be aware of before applying:

• Before the start of the internship, the internship agreement from TNO needs to be signed. For students at a college or university based in the Netherlands, TNO uses the UNL-template (supplemented with a number of specific agreements from TNO). For students of foreign and MBO educational institutions, the TNO internship agreement applies. TNO does not sign any other internship agreements.
• Before the start of the internship, the educational institution will need to confirm in writing that:
  • you are enrolled at the educational institution during the internship, and;
  • the internship takes place as part of the programme of the study.
• The confirmation of educational institution takes place by signing the UNL template or forms prepared by TNO.
• Interns at TNO must be in possession of a Dutch residential address at the start of the internship. Performance of internship activities from abroad is not possible..